In hybrid wireless sensor networks composed of both
static and mobile sensor nodes, the random deployment of stationary nodes may
cause coverage holes in the sensing field. Hence, mobile sensor nodes are added
after the initial deployment to overcome the coverage holes problem. To achieve
optimal coverage, an efficient algorithm should be employed to find the best
positions of the additional mobile nodes. This paper presents a genetic
algorithm that searches for an optimal or near optimal solution to the coverage
holes problem. The proposed algorithm determines the minimum number and the
best locations of the mobile nodes that need to be added after the initial
deployment of the stationary nodes. The performance of the genetic algorithm
was evaluated using several metrics, and the simulation results demonstrated
that the proposed algorithm can optimize the network coverage in terms of the
overall coverage ratio and the number of additional mobile nodes.